Filter aid for preparing dispersions in lubricating oil



United States Patent FILTER AID FOR PREPARING DISPERSIONS IN LUBRICATING OIL George L. Weamer, Berkeley, Calif., assignor to CaliforniaResearch Corporation, San Francisco, Calit'., a

corporation of Delaware No Drawing. Application July 26, 1955 Serial No.524,621

9 Claims. (Cl. 252-344) The present invention relates to a process ofimproving filtration in the preparation of lubricating oil compositionshaving improved acid neutralizing characteristics. Lubricating oilcompositions prepared by the process herein are particularly useful inneutralizing acids formed in internal combustion engines by oxidation.

, This application is a continuation-in-part of application Serial No.261,919, filed December 15, 1951, now abandoned.

During normal operation of internal combustion engines, acids are formedin the lubricating oil itself and in the combustion chamber. The acidsformed in the lubricating oil itself are normally caused by oxidation ofthe lubricating oil during engine operation. The resulting organic acidsand peroxides break down the lubricating oil and contribute to wear bycorrosion. The combustion chamber acids normally come from thecombustion products 'of the fuel. For example, when high sulfur fuelsare used in diesel engines, sulfuric acid is formed from the sulfur.This sulfuric acid finds its way into the crankcase along with theblow-by gases.

Large amounts of detergents are being incorporated in lubricating oilcompositions for use as dispersing agents, and a portion of thesedetergents are incidentally used as neutralizing agents for these acids.For example, calcium cetyl phenate is incorporated into a lubricatingoil composition primarily to serve as a detergent.

However, a portion of this calcium cetyl phenate reacts with thesulfuric acid formed from high sulfur fuels to form calcium sulfate,neutralizing the effect of the acids, and removing part of the detergentfrom its intended purpose.

Rather than use relatively expensive organic com pounds to neutralizethe acids formed during the operation of an engine, it would be morepractical to use other less expensive materials for this purpose.Likewise, it

is more economical to use a detergent in a lubricating larger amounts ofacids per unit weight than the organic detergents.

As taught by Lindstrom and Woodrufi in United States Patent No.2,676,925, lubricating oils having acid-neuv ing oils containingdispersants (e. g., polyvalent metal sulfonates), and the resultingcomposition is filtered.

Because of what appears to be a gel formation, the filtration rate inthe Lindstrom-Woodrufl? process oftentimes is slow and cumbersome,requiring considerable .time. It is therefore a primary object of thisinvention to set. forth a means of improving this filtration rate.

It is another object of this invention to provide a method forinhibiting the formation of a gel prior to the filtration of dispersionsof metal oxides and hydroxides in lubricating oils.

It is a further object of this invention to set forth a method forfacilitating the filtration of dispersions of polyvalent metal oxidesand hydroxides in lubricating oils when said dispersions are prepared bythe use of dihydric alcohols.

These and other objects of this invention will be apparent from theensuing description and the appended claims.

According to the present invention, applicant has discovered that thefiltration step in the process of preparing lubricating oil compositionshaving unexpectedly high acid neutralizing characteristics can befacilitated by the use of a filtering agent; that is, by the use of analkyl phenol (or the calcium salt thereof).

In the formation of the lubricating oil compositions herein, metaloxides and hydroxides are used as initial reactants. Thus, thelubricating oil compositions of this invention are prepared bydissolving an alkaline earth metal base (i. e., an oxide or hydroxide)in a dihydric alcohol (e. g., ethylene glycol). This solution is thenincorporated into a lubricating oil containing an oilsoluble alkalineearth metal dispersant (e. g., an alkaline earth metal sulfonate) and afiltering agent (e. g., an alkyl phenol or a calcium salt thereof),after which the mixture is heated to remove the free dihydric alcohol,and filtered, forming a clear, filterable lubricating oil composition.These lubricating oil compositions contain dispersions of alkaline earthmetal materials which behave in a manner similar to metal oxides andhydroxides.

However, although the metal oxides or hydroxides are the initialreactants, the dihydric alcohol (i. e., an alkylene glycol) is believedto combine therewith to form an alkaline earth metal material whichseems to be an alkaline earth metal basic salt. Thus, as used herein,the alkaline earth metal material, i. e., the basic salt, means theproduct resulting from the reaction ofthe alkaline earth metal base andthe dihydric alcohol. This alkaline earth metal material also can bedescribed as a glycoxide or a glycolated metal base. (The noted reactionis described in Organic Reagents in Inorganic Analysis, by Ibert Mellan,pages 304, published by Blakiston Publishing Co., 1941.) For ease ofdescrib ing the present invention, the term glycoxides will be usedherein as meaning the reaction productof alkaline earth metal oxides (orhydroxides) and dihydric al cohols.

Alkyl phenols which are used according to this invention to facilitatefiltration in the preparation of dispersionsof alkaline earth metalglycoxides in lubricating oils are alkyl phenols containing no more thanthree alkyl groups on the benzene nucleus, each alkyl group containingfrom 4-30 carbon atoms. It is preferred to use an alkyl phenolcontaining one alkyl'group, which alkyl group contains from 12 to 18carbon atoms.

Examples of alkyl phenols which may be used'according to this inventionto facilitate the filtration of dispersions of polyvalent metal oxidesand hydroxides in lubricating oils include: butyl phenol, amyl phenol,hexyl phenol, octyl phenol, decyl phenol, dodecyl phenol, tetradecylphenol, octadecyl phenol, hexadecyl phenol, di-butyl phenol, di-octylphenol, di-hexadecyl phenol, di-octadecyl phenol, tri-butyl phenol,tri-octadecyl phenol, eicosane phenol, triacontyl phenol, and alkylphenols wherein the alkyl groups are derived from alkylene polymers,etc.

The amount of alkyl phenols used to increase the filtrationrate dependson the amount of alkaline earth metal glycoxides dispersed in thelubricating oils. The mol ratio of alkyl phenol (or the calcium saltsthereof) to the alkaline earth metal oxide (or hydroxide) initiallyadded to the dihydric alcohol can vary from about 0.1 to about 1.5. Itis preferred that the mol ratio of alkyl phenol (or the calcium saltsthereof) to the alkaline earth metal oxide (or hydroxide) have a valuein the range of 0.50 to 1.0.

Lubricating oils which are useful as base oils in the process hereininclude a wide variety of lubricating oils such as oils which can bemanufactured by solvent treating, acid treating, etc., various crudeoils, such as paratfinic, naphthenic, or mixed base crude oils, or suchas those which can be obtained by synthesis (e. g., the Fischer-Tropschprocess). Lubricating oils also include those derived from coal productsand synthetic oils, e. g., alkyle'ne polymers (such as polymers ofpropylene, butylene, etc., and mixtures thereof), alkylene oxide typepolymers, dicarboxylic acid esters and liquid esters of acids ofphosphorus. Synthetic oils of the alkylene oxide type polymer which maybe used include those exemplified by alkylene oxide polymers (e. g.,propylene oxide polymers) and derivatives, including alkylene oxidepolymers prepared by polymerizin'g alkylene oxides (e. g., propyleneoxide) in the presence of water or alcohols, e. g., ethyl alcohol, andesters of alkylene oxide type polymers, e. g., acetylated propyleneoxide polymers prepared by acetylating the propylene oxide polymerscontaining hydroxyl groups.

Dispersants which can be used in the process according to this inventioninclude the metal sulfonates exemplified as follows: calcium white oilbenzene sulfonate, barium white oil benzene sulfonate, magnesium whiteoil benzene sulfonate, calcium dipolypropene benzene sulfonate, bariumdipolypropene benzene sulfonate, magnesium dipolypropene benzenesulfonate, calcium mahogany petroleum sulfonate, barium mahoganypetroleum sulfonate, magnesium mahogany petroleum sulfonate, calciumtriacontyl sulfonate, magnesium triacontyl sulfonate, calcium laurylsulfonate, barium lauryl sulfonate, magnesium lauryl sulfonate, etc.

The dispersants can be used in amounts of about 0.1% to 10%, by weight,of said finished composition. However, it is preferred to use from about0.3% to about 2.0%, by Weight, because lubricating oil compositionscontaining these amounts markedly improve the over-all rating of anengine.

Expressed in millimols per kilogram of final lubricating oilcomposition, the dispersants can be used in amounts of about 1 millimolper kilogram to about 110 millimols per kilogram, with a preferred rangeof about 3 millimols per kilogram to about 20-millimols per kilogram.

The dihydric alcohols used in obtaining the lubricating oil compositionof this invention are glycols containing less than 5 carbon atoms; inparticular, these glycols include vicinal-alkane diols having less than5 carbon atoms. Suitable dihydric alcohols include, for example,ethylene glycol, propane diol-1,2; butane diol-2,3; butane dial-1,2;etc. Ethylene glycol is preferred, because thereby, greater amounts ofmetal base are incorporated in the lubricating oil compositions.

The amount of dihydric alcohols used will depend in part upon thedihydric alcohol itself and, as noted hereinabove, on the alkaline earthmetal oxides or hydroxides which are used in the preparation ofdispersions of the alkaline earth metal glycoxide. In general, the useof a low molecular weight dihydric alcohol (e. g., ethylene glycol)results in obtaining a greater amount of the basic materials dispersedin the lubricating oil than the use of a. higher molecular weightdihydric alcohol (e. g., propylene glycol), when both are used in thesame amounts by weight. It is preferred to select a dihydric alcohol inwhich the dispersants and the alkaline earth metal oxides or hydroxideshave the greatest solubility. In the formation of solutions of alkalineearth metal basic materials in glycols, it is beneficial to use certainratios by weight of the dihydric alcohol to the alkaline earth metaloxide or hydroxide. These ratios may vary from about 50:1 to about 2:1,30:1 to about :1 being preferred.

The amount of alkaline earth metal basic materials (i. e., the alkalineearth metal glycoxi'des") which are dispersible in the lubricating oilcompositions herein is dependent on the amount of dispersant which ispresent.

Normally, one part by weight of a dispersant can stably disperse as muchas 0.2 part or more by weight of the alkaline earth metal basicmaterials. For example, one part by weight of an alkaline earth metalmahogany petroleum sulfonate can stably disperse 0.2 part by weight ofan alkaline earth metal basic material. Expressed otherwise, one mol ofan alkaline earth metal mahogany petroleum sulfonate can stably disperseat least 1.75 mols of an alkaline earth metal basic material. Thus, thealkaline earth metal basic materials and dispersants are present in thelubricating oil compositions in such amounts that the basicmaterial/dispersant mol ratios have values of at least 1.75, and as highas 4.0; preferably from about 2.0 to about 3.0.

In terms of the alkaline earth metal oxides and bydroxides which areinitially incorporated into the lubricating oil compositions, theamounts of these oxides and hydroxides can vary from about 0.22% toabout 7.0%, by weight.

The metal of the dispersant may be the same as the metal of the basicmaterial dispersed; or the metal of the dispersant may be difierent fromthe metal of the basic material dispersed. For example, a calciumsulfonate may be used in a lubricating oil composition to stabilize adispersion of a barium basic material, or a calcium sulfonate may beused in a lubricating oil composition to stabilize a dispersion of acalcium basic material.

Alkaline earth metal basic materials are dispersed in lubricating oilcompositions in accordance with this invention by heating a mixture of adispersant, an alkaline earth polyvalent metal oxide and/or hydroxide, adihydric alcohol, and an alkyl phenol (or the calcium salt thereof) inthe lubricating oil to a temperature of about F. to about 400 F. (250 F.to 350 F. being preferred) for a period of time sufficient to promotethe reaction between the alkaline earth metal oxide or hydroxide and thedihydric alcohol, to disperse the metal basic material in thelubricating oil composition, and to remove substantially all of theremaining apparently unreacted dihydric alcohol, after which the mixtureis filtered to remove any apparently unreacted alkaline earth metaloxide or hydroxide. The filtration agent (i. e., alkyl phenol or thecalcium salt thereof) may be in corporated into the lubricating oilcomposition any time prior to the filtration step.

Although no theory is set forth to explain the phenomenon of thisinvention, it is believed that the agents used as filtration aidsinhibit the formation of gel-like substances which slow down thefiltration rate. The method set forth herein can be used wheneverfiltration is impeded by gel-like substances resulting from dispersionsof alkaline earth metal glycox'ides in lubricating oils.

The examples hereinbelow illustrate the etfectiveness of alkyl phenolsin increasing the filtration rate during the preparation of dispersionsof alkaline earth metal glycoxides in lubricating oils. The dispersionin oil was filtered as follows: An 11 cm. Buchner tunnel was set in afilter flask, a filter paper inserted, and 25 g. of Celite spread asevenly as possible over the paper. A vacuum was then applied to thefilter flask so that the absolute pressure within the flask wasmaintained at about 300 mm. of mercury.

In the absence of analkyl phenol as an aid to filtration, only a fewdrops of a dispersion of calcium glycoxide in mineral oil could beobtained in the filter flask. Even a constant scraping of the Celi't'esurface did not assist in any further filtration.

mixture was quite high, the mixture filtered well. filtered mineral oilsolution contained 4.51% calcium,

filtration aid A mixture of grams of calcium hydroxide and 171 grams ofglycol was allowed to blend together over a period of 1 hour. To thismixture was added 48.5 grams of an alkyl phenol having a molecularweight of 340 (the alkyl radical being derived from propylene polymers)and 104 grams of a California solvent-refined parafiin base mineral oilsolution of calcium mahogany petroleum sulfonate (the oil solutioncontained 1.65% calcium). The whole mixture was heated to a temperatureof 400 F. at an absolute pressure of 50 mm. of mercury to remove theethylene glycol. The filtered mineral oil dispersion contained 4.44%calcium, showing 2.79% more calcium in the mineral oil than before.

No difiiculty was experienced in filtering the reaction mixture.

Example 2.?-High molecular weight alkyl phenol as filtration aid Amixture of 10 grams of calcium hydroxide and 171 grams of ethyleneglycol was agitated by vigorous stirring over a period of 1 hour. Tothis mixture was added 22 grams of the same alkyl phenol of Example 1and 104 grams of a California solvent-refined paraffin base mineral oilsolutionof a mahogany petroleum sulfonate. The oil solution contained1.65% calcium. The whole reaction mixture was heated to a temperature of400 F. at 50 mm. of mercury absolute pressure to remove the ethyleneglycol. Although the viscosity of the resultirlig T e showing 2.86% morecalcium than before.

I .Example 3.-Di-tetradecyl phenol as filtration aid A mixture of 7.8grams of calcium hydroxide and 1 27 grams of ethylene glycol wasthoroughly agitated. To the resulting solution was added 77.3 grams of aCalifornia solvent-refined parafiin base mineral oil solution of calciummahogany petroleum sulfonate (the oil solution had a calcium content of1.64%) and 45 grams of di-tetradecyl phenol having a molecular weight of475. (The alkyl group on this phenol was derived from propylene polymershaving an average of 14 carbon atoms per alkyl group.) The reactionmixture was heated to a temperature of 400 F. at an absolute pressure of50 mm. of mercury to remove the ethylene glycol, after which thereaction mixture was filtered and 75 grams of the filtered product wereobtained in 30 minutes by slowly scraping the Celite surface. Themineral oil solution had a calcium content of 3.83%, showing thepresence of 2.19% more calcium than before.

Example 4.-p-Tertiary amyl phenol as filtration aid A mixture of 10.5grams of'calcium hydroxide and 164 grams of ethylene glycol wasthoroughly agitated together, after which was added a solution of 20.2grams of p-tertiary amyl' phenol in 40 grams of a Californiasolvent-refined base oil having a viscosity of 356 SSU at 100 F. To thiswhole mixture was added 140 grams of a California solvent-refinedparaifin-base mineral oil solution of calcium mahogany petroleumsulfonate. (This mineral oil solution contained 1.17% calcium.) Afterthe ethylene glycol had been removed by heating to 400 F. at an absolutepressure of 50 mm. of mercury, the reaction mixture was filtered. Thefiltration was rapid, 120 grams of the filtered calcium hydroxidedispersion in mineral oil being obtained in a period of 2.5 minutes.There was no need to scrape the Celite surface. The filtered mineral oilsolution contained 3.76% calcium, which was 2.59% more calcium than theinitial mineral oil solution of calcium mahogany petroleum sulfonate.

Numerous variations of the method presented here may be employed inpreparing the dispersions of this invention. For example, the polyvalentmetal oxides or 11y droxides may be blended with the dispersantsin' thelubricating oil containing the filtration agent prior to being mixedwith the dihydric alcohol; or the dihydric alcohol, the dispersant, andthe filtration agent may be blended together first, or all of theingredients may be blended together at once. It is preferred to mix thedihydric alcohols and the metal oxides or hydroxides first to obtain acolloidal dispersion or solution of the metal oxides or hydroxides inthe polyhydric alcohols before mixing with the lubricating oil,dispersant, and filtration agent.

I claim:

1. In the process of preparing dispersions of alkaline earth metalglycoxides in lubricating oils by forming an admixture of a lubricatingoil, a dihydric alcohol containing less than 5 carbon atoms, from 0.02%to 7.0%, by weight, based on the oxide, of an inorganic substanceselected from the group consisting of alkaline earth metal oxides andhydroxides, and from 0.1% to 10% by weight of an alkaline earth metalsulfonate, heating said ad mixture to a temperature in the range ofabout F. to about 400 F., removing unreacted dihydric alcohol bydistillation, and filtering said admixture, the improvement comprisingblending into said lubricating oil composition prior to filtration, analkyl phenol having no more than three alkyl groups attached to thebenzene nucleus, each alkyl group containing from 4 to 30 carbon atoms,and wherein the mole ratio of said alkyl phenol to said inorganicsubstance has a value from about 0.1 to about 1.5, wherein the weightratio of dihydric alcohol to said inorganic substance is from 30:1 to10:1, and wherein the mole ratio of'saitl metal inorganic substance tosaid sulfonate has a value from about 1.75 to about 4.0.

2. In the process of preparing dispersions of alkaline earth metalglycoxides in lubricating oils by forming an admixture of a lubricatingoil, a dihydric alcohol containing less than 5 carbon atoms, from 0.02%to 7.0%, by weight, based on the oxide, of an inorganic substanceselected from the group consisting of alkaline earth metal oxides andhydroxides, and from 0.1% to 10% by Weight of an alkaline earth metalsulfonate, heating said admixture to a temperature in the range of about175 F. to about 400 F., removing unreacted dihydric alcohol bydistillation, and filtering said admixture, the improvement comprisingblending into said lubricating oil composition prior to filtraton, analkyl phenol having no more than three alkyl groups attached to thebenzene nucleus, each alkyl group containing from 12 to 18 carbon atoms,and wherein the mole ratio of said alkyl phenol to said inorganicsubstance has a value from about .0.1 to about 1.5, wherein the weightratio of dihydric alcohol to said inorganic substance is from 30:1 to10:1, and wherein the mole ratio of said metal inorganic substance tosaid sulfonate has a value from about 1.75 to about 4.0.

3. In the process of preparing dispersions of alkaline earth metalglycoxides in lubricating oils by forming an admixture of lubricatingoil, a dihydric alcohol containing less than 5 carbon atoms, from 0.02%to 7.0%, by weight, based on the oxide, of an inorganic substanceselected from the group consisting of alkaline earth metal oxides andhydroxides, and from 0.3 to 2% by weight of an alkaline earth metalsulfonate, heating said admixture to a temperature in the range of about175 F. to about 400 F., removing unreacted dihydric alcohol bydistillation, and filtering said admixture, the improvement comprisingblending into the lubricating oil composition prior to filtration, analkyl phenol having one alkyl group attached to the benzene nucleus,said alkyl group containing from 4 to 30 carbon atoms, and wherein themole ratio of said alkyl phenol to said inorganic substance has a valuefrom about 0.1 to about 1.5, wherein the weight ratio of dihydricalcohol to said inorganic substance is from 30:1 to 10:1, and whereinthe mole ratio of said metal inorganic substance to said sulfonate has avalue from about 2.0 to about 3.0.

4. In the process of preparing dispersions of calcium glycoxide inlubricating oils by forming an admixture of a lubricating oil, adihydric alcohol containing less than carbon atoms, from 0.02% to 7% byweight, based on the oxide, of an inorganic substance selected from thegroup consisting of calcium oxide and calcium hydroxide, from 0.1% to byweight of a calcium sulfonate, wherein the mole ratio of said inorganicsubstance to said sulfonate is from about 2.0 to about 3.0, and theweight ratio of said dihydric alcohol to said inorganic substance isfrom :1 to 10:1, heating said admixture to a temperature in the range of175 F. to about 400 F., removing unreacted dihydric alcohol bydistillation, and filtering the admixture, the improvement comprisingblending into the lubricating oil composition prior to the filtrationstep an alkyl phenol having one alkyl group attached to the benzenenucleus, said alkyl group containing from 4 to 30 carbon atoms, andwherein the mole ratio of said alkyl phenol to said inorganic substancehas a value from about 0.1 to 1.5.

5. In the process of preparing dispersions of calcium glycoxide inlubricating oils by forming an admixture of a lubricating oil, ethyleneglycol, from 0.02% to 7% by weight, based on the oxide, of an inorganicsubstance selected from the group consisting of calcium oxide andcalcium hydroxide, from 0.1% to 10% by weight of a calcium sulfonate,wherein the mole ratio of said inorganic substance to said sulfonate isfrom about 2.0 to about 3.0, and the weight ratio of said ethyleneglycol to said inorganic substance is from 30:1 to 10:1, heating saidadmixture to a temperature in the range of 175 F. to about 400 F.,removing unreacted ethylene glycol by distillation, and filtering theadmixture, the improvement comprising blending into the lubricating oilcomposition prior to the filtration step an alkyl phenol having onealkyl group attached to the benzene nucleus, said alkyl group containingfrom 4 to 30 carbon atoms, and wherein the mole ratio of said alkylphenol to said inorganic substance have a value from about 0.1 to 1.5.

6. In the process of preparing dispersions of calcium glycoxide inlubricating oils by forming an admixture of a lubricating oil, ethyleneglycol, from 0.02% to 7% by weight based on the oxide thereof of aninorganic substance selected from the group consisting of calcium oxideand calcium hydroxide, from 0.3% to 2% by weight of a calcium sulfonate,wherein the mole ratio of said inorganic substance to said sulfonate isfrom about 2.0 to about 3.0, and the weight ratio of said ethyleneglycol to said inorganic substance is from 30:1 to 10:1, heating saidadmixture to a temperature in the range of 175 F. to about 400 F.,removing unreacted ethylene glycol by distillation, and filtering theadmixture,

the improvement comprising blending into the lubricating r oilcomposition prior to the filtration step an alkyl phenol having onealkyl group attached to the benzene nucleus, said alkyl group containingfrom 4 to 30 carbon atoms, and wherein the mole ratio of said alkylphenol to said inorganic substance has a value from about 0.1 to 1.5.

7. In the process of preparing dispersions of calcium glycoxide inlubricating oils by forming an admixture of a lubricating oil, ethyleneglycol, from 0.02% to 7% by weight, based on the oxide, of an inorganicsubstance selected from the group consisting of calcium oxide andcalcium hydroxide, from 0.1% to 10% by weight of a calcium sulfonate,wherein the mole ratio of said inorganic substance to said sulfonate isfrom about 2.0 to about 3.0, and the weight ratio of said ethyleneglycol to said inorganic substance is from 30:1 to 10:1, heating saidadmixture to a temperature in the range of 250 F. to about 350 F.,removing unreacted ethylene glycol, and filtering the admixture, theimprovement comprising blending into the lubricating oil compositionprior to the filtration step an alkyl phenol having one alkyl groupattached to the benzene nucleus, said alkyl group containing from 4 to30 carbon atoms, and wherein the mole ratio of said alkyl phenol to saidinorganic substance has a value from about 0.1 to 1.5.

8. In the process of preparing dispersions of calcium glycoxide inlubricating oils by forming an admixture of a petroleum lubricating oil,ethylene glycol, from 0.02% to 7% by weight, based on the oxide, of aninorganic substance selected from the group consisting of calcium oxideand calcium hydroxide, from 0.3% to 2% by weight of a calcium mahoganypetroleum sulfonate, wherein the mole ratio of said inorganic substanceto said sulfonate is from about 2.0 to 3.0, and the weight ratio of saidethylene glycol to said inorganic substance is from 30:1 to 10:1,heating said admixture to a temperature in the rangeof F. to about 400F., removing unreacted ethylene glycol by distillation, and filteringthe admixture, the improvement comprising blending into the lubricatingoil composition prior to the filtration step an alkyl phenol having nomore than three alkyl groups attached to the benzene nucleus, each alkylgroup containing from 4 to 30 carbon atoms, and wherein the mole ratioof said alkyl phenol to said inorganic substance has a value from about0.1 to 1.5.

9. In the process of preparing dispersions of calcium glycoxide inlubricating oils by forming an admixture of a petroleum lubricating oil,ethylene glycol, from 0.02% to 7% by weight, based on the oxide, of aninorganic substance selected from the group consisting of calcium oxideand calcium hydroxide, from 0.3% to 2% by weight of a calcium mahoganypetroleum sulfonate, wherein the mole ratio of said inorganic substanceto said sulfonate is from about 2.0 to about 3.0, and the weight ratioof said ethylene glycol to said inorganic substance is from 30:1 to10:1, heating said admixture to a temperature in the range of 175 F. toabout 400 F., removing unreacted ethylene glycol by distillation, andfiltering the admixture, the improvement comprising blending into thelubricating oil composition prior to the filtration step an alkyl phenolhaving one alkyl group attached to the benzene nucleus, said alkyl groupcontaining from 4 to 30 carbon atoms, and wherein the mole ratio of saidallryl phenol to said inorganic substance has a value from about 0.1 to1.5.

References Cited in the file of this patent UNITED STATES PATENTS2,616,911 Asseff et a1 Nov. 4, 1952 2,676,925 Lindstrom et a1 Apr. 27,1954 2,716,087 Woodruft et al Aug. 23, 1955 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No, 2.,878 l85 March 17, 1959 George L,Weamer It is hereby certified that error appears in the-printedspecification of the above "numbered patent requiring correction andthat the said Letters Patent should read as corrected below.

Column 2, line 43, for "pages" read page column 3, line 62, before"alkaline" insert we alkaline earth metal basic salts; that isdispersions of the column 4, line 22, for O,22%" read 0,02%

Signed and sealed this llth day of August 1959,,

(SEAL) Attest:

KARL H0 AXLINE I ROBERT C. WATSON Attesting Oflicer Commissioner ofPatents

1. IN THE PROCESS OF PREPARING DISPERSIONS OF ALKALINE EARTH METALGLYCOXIDES IN LUBRICATING OILS BY FORMING AN ADMIXTURE OF A LUBRICATINGOIL, A DIHYDRIC ALCOHOL CONTAINING LESS THAN 5 CARBON ATOMS, FROM 0.02%TO 7.0% BY WEIGHT, BASED ON THE OXIDE, OF AN INORGANIC SUBSTANCESELECTED FROM THE GROUP CONSISTING OF ALKALINE EARTH METAL OXIDES ANDHYDROXIDES, AND FROM 0.1% TO 10% BY WEIGHT OF AN ALKALINE EARTH METALSULFONATE, HEATING SAID ADMIXTURE TO A TEMPERATURE IN THE RANGE OF ABOUT175*F. TO ABOUT 400*F., REMOVING UNREACTED DIHYDRIC ALCOHOL BYDISTILLATION, AND FILTERING SAID ADMIXTURE, THE IMPROVEMENT COMPRISINGBLENDING INTO SAID LUBRICATING OIL COMPOSITION PRIOR TO FILTRATION, ANALKYL PHENOL HAVING NO MORE THAN ALKYL GROUPS ATTACHED TO THE BENZENENUCLEUS, EACH ALKYL GROUP CONTAINING FROM 4 TO 30 CARBON ATOMS, ANDWHEREIN THE MOLE RATIO OF SAID ALKYL PHENOL TO SAID INORGANIC SUBSTANCEHAS A VALUE FROM ABOUT 0.1 TO SAID ORGANIC SUBSTANCE IS FROM 30:1 TO10:1, AND WHEREIN THE MOLE RATIO OF SAID METAL INORGANIC SUBSTANCE TOSAID SULOFONATE HAS A VALUE FROM ABOUT 1.75 TO ABOUT 4.0.